From 8fe8f545c6d753ead15e1f4919d39e8f9bb49629 Mon Sep 17 00:00:00 2001
From: Michel Lespinasse <walken@google.com>
Date: Sun, 6 Mar 2011 18:07:50 -0800
Subject: [PATCH 01/11] futex: Update futex_wait_setup comments about locking

Reviving a cleanup I had done about a year ago as part of a larger
futex_set_wait proposal. Over the years, the locking of the hashed
futex queue got improved, so that some of the "rare but normal" race
conditions described in comments can't actually happen anymore.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Darren Hart <dvhltc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110307020750.GA31188@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/futex.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index b766d28accd6..3184d3b9cadf 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1781,13 +1781,14 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
 	 *
 	 * The basic logical guarantee of a futex is that it blocks ONLY
 	 * if cond(var) is known to be true at the time of blocking, for
-	 * any cond.  If we queued after testing *uaddr, that would open
-	 * a race condition where we could block indefinitely with
+	 * any cond.  If we locked the hash-bucket after testing *uaddr, that
+	 * would open a race condition where we could block indefinitely with
 	 * cond(var) false, which would violate the guarantee.
 	 *
-	 * A consequence is that futex_wait() can return zero and absorb
-	 * a wakeup when *uaddr != val on entry to the syscall.  This is
-	 * rare, but normal.
+	 * On the other hand, we insert q and release the hash-bucket only
+	 * after testing *uaddr.  This guarantees that futex_wait() will NOT
+	 * absorb a wakeup if *uaddr does not match the desired values
+	 * while the syscall executes.
 	 */
 retry:
 	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q->key);

From c0c9ed15042ceac7c485813012a0a97316101b57 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 11 Mar 2011 11:51:22 +0100
Subject: [PATCH 02/11] futex: Avoid redudant evaluation of task_pid_vnr()

The result is not going to change under us, so no need to reevaluate
this over and over. Seems to be a leftover from the mechanical mass
conversion of task->pid to task_pid_vnr(tsk).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/futex.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 3184d3b9cadf..773815465bac 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -674,7 +674,7 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
 				struct task_struct *task, int set_waiters)
 {
 	int lock_taken, ret, ownerdied = 0;
-	u32 uval, newval, curval;
+	u32 uval, newval, curval, vpid = task_pid_vnr(task);
 
 retry:
 	ret = lock_taken = 0;
@@ -684,7 +684,7 @@ retry:
 	 * (by doing a 0 -> TID atomic cmpxchg), while holding all
 	 * the locks. It will most likely not succeed.
 	 */
-	newval = task_pid_vnr(task);
+	newval = vpid;
 	if (set_waiters)
 		newval |= FUTEX_WAITERS;
 
@@ -696,7 +696,7 @@ retry:
 	/*
 	 * Detect deadlocks.
 	 */
-	if ((unlikely((curval & FUTEX_TID_MASK) == task_pid_vnr(task))))
+	if ((unlikely((curval & FUTEX_TID_MASK) == vpid)))
 		return -EDEADLK;
 
 	/*
@@ -723,7 +723,7 @@ retry:
 	 */
 	if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
 		/* Keep the OWNER_DIED bit */
-		newval = (curval & ~FUTEX_TID_MASK) | task_pid_vnr(task);
+		newval = (curval & ~FUTEX_TID_MASK) | vpid;
 		ownerdied = 0;
 		lock_taken = 1;
 	}
@@ -2047,9 +2047,9 @@ static int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
 {
 	struct futex_hash_bucket *hb;
 	struct futex_q *this, *next;
-	u32 uval;
 	struct plist_head *head;
 	union futex_key key = FUTEX_KEY_INIT;
+	u32 uval, vpid = task_pid_vnr(current);
 	int ret;
 
 retry:
@@ -2058,7 +2058,7 @@ retry:
 	/*
 	 * We release only a lock we actually own:
 	 */
-	if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
+	if ((uval & FUTEX_TID_MASK) != vpid)
 		return -EPERM;
 
 	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key);
@@ -2074,7 +2074,7 @@ retry:
 	 * anyone else up:
 	 */
 	if (!(uval & FUTEX_OWNER_DIED))
-		uval = cmpxchg_futex_value_locked(uaddr, task_pid_vnr(current), 0);
+		uval = cmpxchg_futex_value_locked(uaddr, vpid, 0);
 
 
 	if (unlikely(uval == -EFAULT))
@@ -2083,7 +2083,7 @@ retry:
 	 * Rare case: we managed to release the lock atomically,
 	 * no need to wake anyone else up:
 	 */
-	if (unlikely(uval == task_pid_vnr(current)))
+	if (unlikely(uval == vpid))
 		goto out_unlock;
 
 	/*

From 522d7decc0370070448a8c28982c8dfd8970489e Mon Sep 17 00:00:00 2001
From: Michel Lespinasse <walken@google.com>
Date: Thu, 10 Mar 2011 18:47:31 -0800
Subject: [PATCH 03/11] futex: Remove redundant pagefault_disable in
 futex_atomic_cmpxchg_inatomic()

kernel/futex.c disables page faults before calling
futex_atomic_cmpxchg_inatomic(), so there is no need to do it again
within that function.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Darren Hart <darren@dvhart.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110311024731.GB26122@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/arm/include/asm/futex.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index b33fe7065b38..7133a8620830 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -95,7 +95,8 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
-	pagefault_disable();	/* implies preempt_disable() */
+	/* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic
+	 * call sites. */
 
 	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
 	"1:	" T(ldr) "	%0, [%3]\n"
@@ -115,8 +116,6 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 	: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
 	: "cc", "memory");
 
-	pagefault_enable();	/* subsumes preempt_enable() */
-
 	return val;
 }
 

From 37a9d912b24f96a0591773e6e6c3642991ae5a70 Mon Sep 17 00:00:00 2001
From: Michel Lespinasse <walken@google.com>
Date: Thu, 10 Mar 2011 18:48:51 -0800
Subject: [PATCH 04/11] futex: Sanitize cmpxchg_futex_value_locked API

The cmpxchg_futex_value_locked API was funny in that it returned either
the original, user-exposed futex value OR an error code such as -EFAULT.
This was confusing at best, and could be a source of livelocks in places
that retry the cmpxchg_futex_value_locked after trying to fix the issue
by running fault_in_user_writeable().

This change makes the cmpxchg_futex_value_locked API more similar to the
get_futex_value_locked one, returning an error code and updating the
original value through a reference argument.

Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>  [tile]
Acked-by: Tony Luck <tony.luck@intel.com>  [ia64]
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michal Simek <monstr@monstr.eu>  [microblaze]
Acked-by: David Howells <dhowells@redhat.com> [frv]
Cc: Darren Hart <darren@dvhart.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110311024851.GC26122@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/alpha/include/asm/futex.h      | 22 +++++++-------
 arch/arm/include/asm/futex.h        | 18 +++++++-----
 arch/frv/include/asm/futex.h        |  3 +-
 arch/ia64/include/asm/futex.h       |  9 ++++--
 arch/microblaze/include/asm/futex.h | 24 ++++++++-------
 arch/mips/include/asm/futex.h       | 32 ++++++++++----------
 arch/parisc/include/asm/futex.h     | 18 ++++++------
 arch/powerpc/include/asm/futex.h    | 20 +++++++------
 arch/s390/include/asm/futex.h       |  4 +--
 arch/s390/include/asm/uaccess.h     |  2 +-
 arch/s390/lib/uaccess.h             |  4 +--
 arch/s390/lib/uaccess_pt.c          | 13 +++++----
 arch/s390/lib/uaccess_std.c         |  6 ++--
 arch/sh/include/asm/futex-irq.h     |  9 +++---
 arch/sh/include/asm/futex.h         |  5 ++--
 arch/sparc/include/asm/futex_64.h   | 16 ++++++----
 arch/tile/include/asm/futex.h       |  7 +++--
 arch/x86/include/asm/futex.h        | 16 +++++-----
 include/asm-generic/futex.h         |  3 +-
 kernel/futex.c                      | 45 ++++++++++-------------------
 20 files changed, 144 insertions(+), 132 deletions(-)

diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h
index 945de222ab91..c4e5c2850cce 100644
--- a/arch/alpha/include/asm/futex.h
+++ b/arch/alpha/include/asm/futex.h
@@ -81,21 +81,22 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
-	int prev, cmp;
+	int ret = 0, prev, cmp;
 
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
 	__asm__ __volatile__ (
 		__ASM_SMP_MB
-	"1:	ldl_l	%0,0(%2)\n"
-	"	cmpeq	%0,%3,%1\n"
-	"	beq	%1,3f\n"
-	"	mov	%4,%1\n"
-	"2:	stl_c	%1,0(%2)\n"
-	"	beq	%1,4f\n"
+	"1:	ldl_l	%1,0(%3)\n"
+	"	cmpeq	%1,%4,%2\n"
+	"	beq	%2,3f\n"
+	"	mov	%5,%2\n"
+	"2:	stl_c	%2,0(%3)\n"
+	"	beq	%2,4f\n"
 	"3:	.subsection 2\n"
 	"4:	br	1b\n"
 	"	.previous\n"
@@ -105,11 +106,12 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 	"	.long	2b-.\n"
 	"	lda	$31,3b-2b(%0)\n"
 	"	.previous\n"
-	:	"=&r"(prev), "=&r"(cmp)
+	:	"+r"(ret), "=&r"(prev), "=&r"(cmp)
 	:	"r"(uaddr), "r"((long)oldval), "r"(newval)
 	:	"memory");
 
-	return prev;
+	*uval = prev;
+	return ret;
 }
 
 #endif /* __KERNEL__ */
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 7133a8620830..d20b78fce758 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -88,9 +88,10 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
-	int val;
+	int ret = 0, val;
 
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
@@ -99,24 +100,25 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 	 * call sites. */
 
 	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
-	"1:	" T(ldr) "	%0, [%3]\n"
-	"	teq	%0, %1\n"
+	"1:	" T(ldr) "	%1, [%4]\n"
+	"	teq	%1, %2\n"
 	"	it	eq	@ explicit IT needed for the 2b label\n"
-	"2:	" T(streq) "	%2, [%3]\n"
+	"2:	" T(streq) "	%3, [%4]\n"
 	"3:\n"
 	"	.pushsection __ex_table,\"a\"\n"
 	"	.align	3\n"
 	"	.long	1b, 4f, 2b, 4f\n"
 	"	.popsection\n"
 	"	.pushsection .fixup,\"ax\"\n"
-	"4:	mov	%0, %4\n"
+	"4:	mov	%0, %5\n"
 	"	b	3b\n"
 	"	.popsection"
-	: "=&r" (val)
+	: "+r" (ret), "=&r" (val)
 	: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
 	: "cc", "memory");
 
-	return val;
+	*uval = val;
+	return ret;
 }
 
 #endif /* !SMP */
diff --git a/arch/frv/include/asm/futex.h b/arch/frv/include/asm/futex.h
index 08b3d1da3583..0548f8e4d11e 100644
--- a/arch/frv/include/asm/futex.h
+++ b/arch/frv/include/asm/futex.h
@@ -10,7 +10,8 @@
 extern int futex_atomic_op_inuser(int encoded_op, int __user *uaddr);
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
 	return -ENOSYS;
 }
diff --git a/arch/ia64/include/asm/futex.h b/arch/ia64/include/asm/futex.h
index c7f0f062239c..b0728404dad0 100644
--- a/arch/ia64/include/asm/futex.h
+++ b/arch/ia64/include/asm/futex.h
@@ -100,23 +100,26 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
 	{
-		register unsigned long r8 __asm ("r8");
+		register unsigned long r8 __asm ("r8") = 0;
+		unsigned long prev;
 		__asm__ __volatile__(
 			"	mf;;					\n"
 			"	mov ar.ccv=%3;;				\n"
 			"[1:]	cmpxchg4.acq %0=[%1],%2,ar.ccv		\n"
 			"	.xdata4 \"__ex_table\", 1b-., 2f-.	\n"
 			"[2:]"
-			: "=r" (r8)
+			: "=r" (prev)
 			: "r" (uaddr), "r" (newval),
 			  "rO" ((long) (unsigned) oldval)
 			: "memory");
+		*uval = prev;
 		return r8;
 	}
 }
diff --git a/arch/microblaze/include/asm/futex.h b/arch/microblaze/include/asm/futex.h
index ad3fd61b2fe7..fa019ed65dfb 100644
--- a/arch/microblaze/include/asm/futex.h
+++ b/arch/microblaze/include/asm/futex.h
@@ -94,31 +94,33 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
-	int prev, cmp;
+	int ret = 0, prev, cmp;
 
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
-	__asm__ __volatile__ ("1:	lwx	%0, %2, r0;		\
-					cmp	%1, %0, %3;		\
-					beqi	%1, 3f;			\
-				2:	swx	%4, %2, r0;		\
-					addic	%1, r0, 0;		\
-					bnei	%1, 1b;			\
+	__asm__ __volatile__ ("1:	lwx	%1, %3, r0;		\
+					cmp	%2, %1, %4;		\
+					beqi	%2, 3f;			\
+				2:	swx	%5, %3, r0;		\
+					addic	%2, r0, 0;		\
+					bnei	%2, 1b;			\
 				3:					\
 				.section .fixup,\"ax\";			\
 				4:	brid	3b;			\
-					addik	%0, r0, %5;		\
+					addik	%0, r0, %6;		\
 				.previous;				\
 				.section __ex_table,\"a\";		\
 				.word	1b,4b,2b,4b;			\
 				.previous;"				\
-		: "=&r" (prev), "=&r"(cmp)				\
+		: "+r" (ret), "=&r" (prev), "=&r"(cmp)	\
 		: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT));
 
-	return prev;
+	*uval = prev;
+	return ret;
 }
 
 #endif /* __KERNEL__ */
diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h
index b9cce90346cf..692a24bd83b7 100644
--- a/arch/mips/include/asm/futex.h
+++ b/arch/mips/include/asm/futex.h
@@ -132,9 +132,10 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
-	int retval;
+	int ret = 0, val;
 
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
@@ -145,25 +146,25 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 		"	.set	push					\n"
 		"	.set	noat					\n"
 		"	.set	mips3					\n"
-		"1:	ll	%0, %2					\n"
-		"	bne	%0, %z3, 3f				\n"
+		"1:	ll	%1, %3					\n"
+		"	bne	%1, %z4, 3f				\n"
 		"	.set	mips0					\n"
-		"	move	$1, %z4					\n"
+		"	move	$1, %z5					\n"
 		"	.set	mips3					\n"
-		"2:	sc	$1, %1					\n"
+		"2:	sc	$1, %2					\n"
 		"	beqzl	$1, 1b					\n"
 		__WEAK_LLSC_MB
 		"3:							\n"
 		"	.set	pop					\n"
 		"	.section .fixup,\"ax\"				\n"
-		"4:	li	%0, %5					\n"
+		"4:	li	%0, %6					\n"
 		"	j	3b					\n"
 		"	.previous					\n"
 		"	.section __ex_table,\"a\"			\n"
 		"	"__UA_ADDR "\t1b, 4b				\n"
 		"	"__UA_ADDR "\t2b, 4b				\n"
 		"	.previous					\n"
-		: "=&r" (retval), "=R" (*uaddr)
+		: "+r" (ret), "=&r" (val), "=R" (*uaddr)
 		: "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT)
 		: "memory");
 	} else if (cpu_has_llsc) {
@@ -172,31 +173,32 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 		"	.set	push					\n"
 		"	.set	noat					\n"
 		"	.set	mips3					\n"
-		"1:	ll	%0, %2					\n"
-		"	bne	%0, %z3, 3f				\n"
+		"1:	ll	%1, %3					\n"
+		"	bne	%1, %z4, 3f				\n"
 		"	.set	mips0					\n"
-		"	move	$1, %z4					\n"
+		"	move	$1, %z5					\n"
 		"	.set	mips3					\n"
-		"2:	sc	$1, %1					\n"
+		"2:	sc	$1, %2					\n"
 		"	beqz	$1, 1b					\n"
 		__WEAK_LLSC_MB
 		"3:							\n"
 		"	.set	pop					\n"
 		"	.section .fixup,\"ax\"				\n"
-		"4:	li	%0, %5					\n"
+		"4:	li	%0, %6					\n"
 		"	j	3b					\n"
 		"	.previous					\n"
 		"	.section __ex_table,\"a\"			\n"
 		"	"__UA_ADDR "\t1b, 4b				\n"
 		"	"__UA_ADDR "\t2b, 4b				\n"
 		"	.previous					\n"
-		: "=&r" (retval), "=R" (*uaddr)
+		: "+r" (ret), "=&r" (val), "=R" (*uaddr)
 		: "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT)
 		: "memory");
 	} else
 		return -ENOSYS;
 
-	return retval;
+	*uval = val;
+	return ret;
 }
 
 #endif
diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h
index 0c705c3a55ef..4c6d8672325b 100644
--- a/arch/parisc/include/asm/futex.h
+++ b/arch/parisc/include/asm/futex.h
@@ -51,10 +51,10 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 
 /* Non-atomic version */
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
-	int err = 0;
-	int uval;
+	int val;
 
 	/* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
 	 * our gateway page, and causes no end of trouble...
@@ -65,12 +65,12 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
-	err = get_user(uval, uaddr);
-	if (err) return -EFAULT;
-	if (uval == oldval)
-		err = put_user(newval, uaddr);
-	if (err) return -EFAULT;
-	return uval;
+	if (get_user(val, uaddr))
+		return -EFAULT;
+	if (val == oldval && put_user(newval, uaddr))
+		return -EFAULT;
+	*uval = val;
+	return 0;
 }
 
 #endif /*__KERNEL__*/
diff --git a/arch/powerpc/include/asm/futex.h b/arch/powerpc/include/asm/futex.h
index 7c589ef81fb0..631e8da60064 100644
--- a/arch/powerpc/include/asm/futex.h
+++ b/arch/powerpc/include/asm/futex.h
@@ -82,35 +82,37 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
-	int prev;
+	int ret = 0, prev;
 
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
         __asm__ __volatile__ (
         PPC_RELEASE_BARRIER
-"1:     lwarx   %0,0,%2         # futex_atomic_cmpxchg_inatomic\n\
-        cmpw    0,%0,%3\n\
+"1:     lwarx   %1,0,%3         # futex_atomic_cmpxchg_inatomic\n\
+        cmpw    0,%1,%4\n\
         bne-    3f\n"
-        PPC405_ERR77(0,%2)
-"2:     stwcx.  %4,0,%2\n\
+        PPC405_ERR77(0,%3)
+"2:     stwcx.  %5,0,%3\n\
         bne-    1b\n"
         PPC_ACQUIRE_BARRIER
 "3:	.section .fixup,\"ax\"\n\
-4:	li	%0,%5\n\
+4:	li	%0,%6\n\
 	b	3b\n\
 	.previous\n\
 	.section __ex_table,\"a\"\n\
 	.align 3\n\
 	" PPC_LONG "1b,4b,2b,4b\n\
 	.previous" \
-        : "=&r" (prev), "+m" (*uaddr)
+        : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
         : "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT)
         : "cc", "memory");
 
-        return prev;
+	*uval = prev;
+        return ret;
 }
 
 #endif /* __KERNEL__ */
diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h
index 5c5d02de49e9..27ac515ef59c 100644
--- a/arch/s390/include/asm/futex.h
+++ b/arch/s390/include/asm/futex.h
@@ -39,13 +39,13 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	return ret;
 }
 
-static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr,
+static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
 						int oldval, int newval)
 {
 	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
-	return uaccess.futex_atomic_cmpxchg(uaddr, oldval, newval);
+	return uaccess.futex_atomic_cmpxchg(uval, uaddr, oldval, newval);
 }
 
 #endif /* __KERNEL__ */
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index d6b1ed0ec52b..549adf6a9b8b 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -84,7 +84,7 @@ struct uaccess_ops {
 	size_t (*strnlen_user)(size_t, const char __user *);
 	size_t (*strncpy_from_user)(size_t, const char __user *, char *);
 	int (*futex_atomic_op)(int op, int __user *, int oparg, int *old);
-	int (*futex_atomic_cmpxchg)(int __user *, int old, int new);
+	int (*futex_atomic_cmpxchg)(int *, int __user *, int old, int new);
 };
 
 extern struct uaccess_ops uaccess;
diff --git a/arch/s390/lib/uaccess.h b/arch/s390/lib/uaccess.h
index 126011df14f1..89a80674e44b 100644
--- a/arch/s390/lib/uaccess.h
+++ b/arch/s390/lib/uaccess.h
@@ -12,12 +12,12 @@ extern size_t copy_from_user_std(size_t, const void __user *, void *);
 extern size_t copy_to_user_std(size_t, void __user *, const void *);
 extern size_t strnlen_user_std(size_t, const char __user *);
 extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
-extern int futex_atomic_cmpxchg_std(int __user *, int, int);
+extern int futex_atomic_cmpxchg_std(int *, int __user *, int, int);
 extern int futex_atomic_op_std(int, int __user *, int, int *);
 
 extern size_t copy_from_user_pt(size_t, const void __user *, void *);
 extern size_t copy_to_user_pt(size_t, void __user *, const void *);
 extern int futex_atomic_op_pt(int, int __user *, int, int *);
-extern int futex_atomic_cmpxchg_pt(int __user *, int, int);
+extern int futex_atomic_cmpxchg_pt(int *, int __user *, int, int);
 
 #endif /* __ARCH_S390_LIB_UACCESS_H */
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index 404f2de296dc..b3cebcd52f5c 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -354,26 +354,29 @@ int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
 	return ret;
 }
 
-static int __futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+static int __futex_atomic_cmpxchg_pt(int *uval, int __user *uaddr,
+				     int oldval, int newval)
 {
 	int ret;
 
 	asm volatile("0: cs   %1,%4,0(%5)\n"
-		     "1: lr   %0,%1\n"
+		     "1: la   %0,0\n"
 		     "2:\n"
 		     EX_TABLE(0b,2b) EX_TABLE(1b,2b)
 		     : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
 		     : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
 		     : "cc", "memory" );
+	*uval = oldval;
 	return ret;
 }
 
-int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+int futex_atomic_cmpxchg_pt(int *uval, int __user *uaddr,
+			    int oldval, int newval)
 {
 	int ret;
 
 	if (segment_eq(get_fs(), KERNEL_DS))
-		return __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
+		return __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
 	spin_lock(&current->mm->page_table_lock);
 	uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
 	if (!uaddr) {
@@ -382,7 +385,7 @@ int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
 	}
 	get_page(virt_to_page(uaddr));
 	spin_unlock(&current->mm->page_table_lock);
-	ret = __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
+	ret = __futex_atomic_cmpxchg_pt(uval, uaddr, oldval, newval);
 	put_page(virt_to_page(uaddr));
 	return ret;
 }
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
index a6c4f7ed24a4..1d6643c0b95f 100644
--- a/arch/s390/lib/uaccess_std.c
+++ b/arch/s390/lib/uaccess_std.c
@@ -287,19 +287,21 @@ int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old)
 	return ret;
 }
 
-int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval)
+int futex_atomic_cmpxchg_std(int *uval, int __user *uaddr,
+			     int oldval, int newval)
 {
 	int ret;
 
 	asm volatile(
 		"   sacf 256\n"
 		"0: cs   %1,%4,0(%5)\n"
-		"1: lr   %0,%1\n"
+		"1: la   %0,0\n"
 		"2: sacf 0\n"
 		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
 		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
 		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
 		: "cc", "memory" );
+	*uval = oldval;
 	return ret;
 }
 
diff --git a/arch/sh/include/asm/futex-irq.h b/arch/sh/include/asm/futex-irq.h
index a9f16a7f9aea..7b701cbd1e84 100644
--- a/arch/sh/include/asm/futex-irq.h
+++ b/arch/sh/include/asm/futex-irq.h
@@ -88,7 +88,8 @@ static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr,
 	return ret;
 }
 
-static inline int atomic_futex_op_cmpxchg_inatomic(int __user *uaddr,
+static inline int atomic_futex_op_cmpxchg_inatomic(int *uval,
+						   int __user *uaddr,
 						   int oldval, int newval)
 {
 	unsigned long flags;
@@ -102,10 +103,8 @@ static inline int atomic_futex_op_cmpxchg_inatomic(int __user *uaddr,
 
 	local_irq_restore(flags);
 
-	if (ret)
-		return ret;
-
-	return prev;
+	*uval = prev;
+	return ret;
 }
 
 #endif /* __ASM_SH_FUTEX_IRQ_H */
diff --git a/arch/sh/include/asm/futex.h b/arch/sh/include/asm/futex.h
index 68256ec5fa35..a8a5125dc9b4 100644
--- a/arch/sh/include/asm/futex.h
+++ b/arch/sh/include/asm/futex.h
@@ -65,12 +65,13 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
-	return atomic_futex_op_cmpxchg_inatomic(uaddr, oldval, newval);
+	return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
 }
 
 #endif /* __KERNEL__ */
diff --git a/arch/sparc/include/asm/futex_64.h b/arch/sparc/include/asm/futex_64.h
index 47f95839dc69..e0862200d6a1 100644
--- a/arch/sparc/include/asm/futex_64.h
+++ b/arch/sparc/include/asm/futex_64.h
@@ -85,26 +85,30 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
+	int ret = 0;
+
 	__asm__ __volatile__(
-	"\n1:	casa	[%3] %%asi, %2, %0\n"
+	"\n1:	casa	[%4] %%asi, %3, %1\n"
 	"2:\n"
 	"	.section .fixup,#alloc,#execinstr\n"
 	"	.align	4\n"
 	"3:	sethi	%%hi(2b), %0\n"
 	"	jmpl	%0 + %%lo(2b), %%g0\n"
-	"	 mov	%4, %0\n"
+	"	mov	%5, %0\n"
 	"	.previous\n"
 	"	.section __ex_table,\"a\"\n"
 	"	.align	4\n"
 	"	.word	1b, 3b\n"
 	"	.previous\n"
-	: "=r" (newval)
-	: "0" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT)
+	: "+r" (ret), "=r" (newval)
+	: "1" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT)
 	: "memory");
 
-	return newval;
+	*uval = newval;
+	return ret;
 }
 
 #endif /* !(_SPARC64_FUTEX_H) */
diff --git a/arch/tile/include/asm/futex.h b/arch/tile/include/asm/futex.h
index fe0d10dcae57..664b20aa2584 100644
--- a/arch/tile/include/asm/futex.h
+++ b/arch/tile/include/asm/futex.h
@@ -119,8 +119,8 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	return ret;
 }
 
-static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
-						int newval)
+static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+						int oldval, int newval)
 {
 	struct __get_user asm_ret;
 
@@ -128,7 +128,8 @@ static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
 		return -EFAULT;
 
 	asm_ret = futex_cmpxchg(uaddr, oldval, newval);
-	return asm_ret.err ? asm_ret.err : asm_ret.val;
+	*uval = asm_ret.val;
+	return asm_ret.err;
 }
 
 #ifndef __tilegx__
diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index 1f11ce44e956..884c0b5676f4 100644
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -109,9 +109,10 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	return ret;
 }
 
-static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
-						int newval)
+static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+						int oldval, int newval)
 {
+	int ret = 0;
 
 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
 	/* Real i386 machines have no cmpxchg instruction */
@@ -122,18 +123,19 @@ static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval,
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
 		return -EFAULT;
 
-	asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %3, %1\n"
+	asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
 		     "2:\t.section .fixup, \"ax\"\n"
-		     "3:\tmov     %2, %0\n"
+		     "3:\tmov     %3, %0\n"
 		     "\tjmp     2b\n"
 		     "\t.previous\n"
 		     _ASM_EXTABLE(1b, 3b)
-		     : "=a" (oldval), "+m" (*uaddr)
-		     : "i" (-EFAULT), "r" (newval), "0" (oldval)
+		     : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
+		     : "i" (-EFAULT), "r" (newval), "1" (oldval)
 		     : "memory"
 	);
 
-	return oldval;
+	*uval = oldval;
+	return ret;
 }
 
 #endif
diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
index 3c2344f48136..132bf5227b44 100644
--- a/include/asm-generic/futex.h
+++ b/include/asm-generic/futex.h
@@ -48,7 +48,8 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
+			      int oldval, int newval)
 {
 	return -ENOSYS;
 }
diff --git a/kernel/futex.c b/kernel/futex.c
index 773815465bac..237f14bfc022 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -381,15 +381,16 @@ static struct futex_q *futex_top_waiter(struct futex_hash_bucket *hb,
 	return NULL;
 }
 
-static u32 cmpxchg_futex_value_locked(u32 __user *uaddr, u32 uval, u32 newval)
+static int cmpxchg_futex_value_locked(u32 *curval, u32 __user *uaddr,
+				      u32 uval, u32 newval)
 {
-	u32 curval;
+	int ret;
 
 	pagefault_disable();
-	curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval);
+	ret = futex_atomic_cmpxchg_inatomic(curval, uaddr, uval, newval);
 	pagefault_enable();
 
-	return curval;
+	return ret;
 }
 
 static int get_futex_value_locked(u32 *dest, u32 __user *from)
@@ -688,9 +689,7 @@ retry:
 	if (set_waiters)
 		newval |= FUTEX_WAITERS;
 
-	curval = cmpxchg_futex_value_locked(uaddr, 0, newval);
-
-	if (unlikely(curval == -EFAULT))
+	if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, 0, newval)))
 		return -EFAULT;
 
 	/*
@@ -728,9 +727,7 @@ retry:
 		lock_taken = 1;
 	}
 
-	curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
-
-	if (unlikely(curval == -EFAULT))
+	if (unlikely(cmpxchg_futex_value_locked(&curval, uaddr, uval, newval)))
 		return -EFAULT;
 	if (unlikely(curval != uval))
 		goto retry;
@@ -843,9 +840,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
 
 		newval = FUTEX_WAITERS | task_pid_vnr(new_owner);
 
-		curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
-
-		if (curval == -EFAULT)
+		if (cmpxchg_futex_value_locked(&curval, uaddr, uval, newval))
 			ret = -EFAULT;
 		else if (curval != uval)
 			ret = -EINVAL;
@@ -880,10 +875,8 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval)
 	 * There is no waiter, so we unlock the futex. The owner died
 	 * bit has not to be preserved here. We are the owner:
 	 */
-	oldval = cmpxchg_futex_value_locked(uaddr, uval, 0);
-
-	if (oldval == -EFAULT)
-		return oldval;
+	if (cmpxchg_futex_value_locked(&oldval, uaddr, uval, 0))
+		return -EFAULT;
 	if (oldval != uval)
 		return -EAGAIN;
 
@@ -1578,9 +1571,7 @@ retry:
 	while (1) {
 		newval = (uval & FUTEX_OWNER_DIED) | newtid;
 
-		curval = cmpxchg_futex_value_locked(uaddr, uval, newval);
-
-		if (curval == -EFAULT)
+		if (cmpxchg_futex_value_locked(&curval, uaddr, uval, newval))
 			goto handle_fault;
 		if (curval == uval)
 			break;
@@ -2073,11 +2064,8 @@ retry:
 	 * again. If it succeeds then we can return without waking
 	 * anyone else up:
 	 */
-	if (!(uval & FUTEX_OWNER_DIED))
-		uval = cmpxchg_futex_value_locked(uaddr, vpid, 0);
-
-
-	if (unlikely(uval == -EFAULT))
+	if (!(uval & FUTEX_OWNER_DIED) &&
+	    cmpxchg_futex_value_locked(&uval, uaddr, vpid, 0))
 		goto pi_faulted;
 	/*
 	 * Rare case: we managed to release the lock atomically,
@@ -2464,9 +2452,7 @@ retry:
 		 * userspace.
 		 */
 		mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED;
-		nval = futex_atomic_cmpxchg_inatomic(uaddr, uval, mval);
-
-		if (nval == -EFAULT)
+		if (futex_atomic_cmpxchg_inatomic(&nval, uaddr, uval, mval))
 			return -1;
 
 		if (nval != uval)
@@ -2679,8 +2665,7 @@ static int __init futex_init(void)
 	 * implementation, the non-functional ones will return
 	 * -ENOSYS.
 	 */
-	curval = cmpxchg_futex_value_locked(NULL, 0, 0);
-	if (curval == -EFAULT)
+	if (cmpxchg_futex_value_locked(&curval, NULL, 0, 0) == -EFAULT)
 		futex_cmpxchg_enabled = 1;
 
 	for (i = 0; i < ARRAY_SIZE(futex_queues); i++) {

From 8d7718aa082aaf30a0b4989e1f04858952f941bc Mon Sep 17 00:00:00 2001
From: Michel Lespinasse <walken@google.com>
Date: Thu, 10 Mar 2011 18:50:58 -0800
Subject: [PATCH 05/11] futex: Sanitize futex ops argument types

Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic
prototypes to use u32 types for the futex as this is the data type the
futex core code uses all over the place.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Darren Hart <darren@dvhart.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110311025058.GD26122@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/alpha/include/asm/futex.h      | 13 +++++++------
 arch/arm/include/asm/futex.h        | 13 +++++++------
 arch/frv/include/asm/futex.h        |  6 +++---
 arch/frv/kernel/futex.c             | 14 +++++++-------
 arch/ia64/include/asm/futex.h       | 10 +++++-----
 arch/microblaze/include/asm/futex.h | 13 +++++++------
 arch/mips/include/asm/futex.h       | 13 +++++++------
 arch/parisc/include/asm/futex.h     | 12 ++++++------
 arch/powerpc/include/asm/futex.h    | 13 +++++++------
 arch/s390/include/asm/futex.h       | 10 +++++-----
 arch/s390/include/asm/uaccess.h     |  4 ++--
 arch/s390/lib/uaccess.h             |  8 ++++----
 arch/s390/lib/uaccess_pt.c          | 12 ++++++------
 arch/s390/lib/uaccess_std.c         |  6 +++---
 arch/sh/include/asm/futex-irq.h     | 19 ++++++++++---------
 arch/sh/include/asm/futex.h         | 10 +++++-----
 arch/sparc/include/asm/futex_64.h   |  8 ++++----
 arch/tile/include/asm/futex.h       | 24 ++++++++++++------------
 arch/x86/include/asm/futex.h        | 10 +++++-----
 include/asm-generic/futex.h         |  8 ++++----
 20 files changed, 116 insertions(+), 110 deletions(-)

diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h
index c4e5c2850cce..e8a761aee088 100644
--- a/arch/alpha/include/asm/futex.h
+++ b/arch/alpha/include/asm/futex.h
@@ -29,7 +29,7 @@
 	:	"r" (uaddr), "r"(oparg)				\
 	:	"memory")
 
-static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -39,7 +39,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -81,12 +81,13 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	int ret = 0, prev, cmp;
+	int ret = 0, cmp;
+	u32 prev;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	__asm__ __volatile__ (
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index d20b78fce758..0e29d8e6a5c2 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -35,7 +35,7 @@
 	: "cc", "memory")
 
 static inline int
-futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -46,7 +46,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();	/* implies preempt_disable() */
@@ -88,12 +88,13 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	int ret = 0, val;
+	int ret = 0;
+	u32 val;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	/* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic
diff --git a/arch/frv/include/asm/futex.h b/arch/frv/include/asm/futex.h
index 0548f8e4d11e..4bea27f50a7a 100644
--- a/arch/frv/include/asm/futex.h
+++ b/arch/frv/include/asm/futex.h
@@ -7,11 +7,11 @@
 #include <asm/errno.h>
 #include <asm/uaccess.h>
 
-extern int futex_atomic_op_inuser(int encoded_op, int __user *uaddr);
+extern int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr);
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
 	return -ENOSYS;
 }
diff --git a/arch/frv/kernel/futex.c b/arch/frv/kernel/futex.c
index 14f64b054c7e..d155ca9e5098 100644
--- a/arch/frv/kernel/futex.c
+++ b/arch/frv/kernel/futex.c
@@ -18,7 +18,7 @@
  * the various futex operations; MMU fault checking is ignored under no-MMU
  * conditions
  */
-static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, int *_oldval)
+static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr, int *_oldval)
 {
 	int oldval, ret;
 
@@ -50,7 +50,7 @@ static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr, int *_o
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, int *_oldval)
+static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr, int *_oldval)
 {
 	int oldval, ret;
 
@@ -83,7 +83,7 @@ static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr, int *_o
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, int *_oldval)
+static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr, int *_oldval)
 {
 	int oldval, ret;
 
@@ -116,7 +116,7 @@ static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr, int *_ol
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, int *_oldval)
+static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr, int *_oldval)
 {
 	int oldval, ret;
 
@@ -149,7 +149,7 @@ static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr, int *_o
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, int *_oldval)
+static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr, int *_oldval)
 {
 	int oldval, ret;
 
@@ -186,7 +186,7 @@ static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr, int *_o
 /*
  * do the futex operations
  */
-int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -197,7 +197,7 @@ int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
diff --git a/arch/ia64/include/asm/futex.h b/arch/ia64/include/asm/futex.h
index b0728404dad0..8428525ddb22 100644
--- a/arch/ia64/include/asm/futex.h
+++ b/arch/ia64/include/asm/futex.h
@@ -46,7 +46,7 @@ do {									\
 } while (0)
 
 static inline int
-futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -56,7 +56,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -100,10 +100,10 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	{
diff --git a/arch/microblaze/include/asm/futex.h b/arch/microblaze/include/asm/futex.h
index fa019ed65dfb..b0526d2716fa 100644
--- a/arch/microblaze/include/asm/futex.h
+++ b/arch/microblaze/include/asm/futex.h
@@ -29,7 +29,7 @@
 })
 
 static inline int
-futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -39,7 +39,7 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -94,12 +94,13 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	int ret = 0, prev, cmp;
+	int ret = 0, cmp;
+	u32 prev;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	__asm__ __volatile__ ("1:	lwx	%1, %3, r0;		\
diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h
index 692a24bd83b7..6ebf1734b411 100644
--- a/arch/mips/include/asm/futex.h
+++ b/arch/mips/include/asm/futex.h
@@ -75,7 +75,7 @@
 }
 
 static inline int
-futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -85,7 +85,7 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -132,12 +132,13 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	int ret = 0, val;
+	int ret = 0;
+	u32 val;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	if (cpu_has_llsc && R10000_LLSC_WAR) {
diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h
index 4c6d8672325b..67a33cc27ef2 100644
--- a/arch/parisc/include/asm/futex.h
+++ b/arch/parisc/include/asm/futex.h
@@ -8,7 +8,7 @@
 #include <asm/errno.h>
 
 static inline int
-futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -18,7 +18,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -51,10 +51,10 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 
 /* Non-atomic version */
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	int val;
+	u32 val;
 
 	/* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
 	 * our gateway page, and causes no end of trouble...
@@ -62,7 +62,7 @@ futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
 	if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
 		return -EFAULT;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	if (get_user(val, uaddr))
diff --git a/arch/powerpc/include/asm/futex.h b/arch/powerpc/include/asm/futex.h
index 631e8da60064..c94e4a3fe2ef 100644
--- a/arch/powerpc/include/asm/futex.h
+++ b/arch/powerpc/include/asm/futex.h
@@ -30,7 +30,7 @@
 	: "b" (uaddr), "i" (-EFAULT), "r" (oparg) \
 	: "cr0", "memory")
 
-static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -40,7 +40,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -82,12 +82,13 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	int ret = 0, prev;
+	int ret = 0;
+	u32 prev;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
         __asm__ __volatile__ (
diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h
index 27ac515ef59c..81cf36b691f1 100644
--- a/arch/s390/include/asm/futex.h
+++ b/arch/s390/include/asm/futex.h
@@ -7,7 +7,7 @@
 #include <linux/uaccess.h>
 #include <asm/errno.h>
 
-static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -18,7 +18,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -39,10 +39,10 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	return ret;
 }
 
-static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-						int oldval, int newval)
+static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+						u32 oldval, u32 newval)
 {
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	return uaccess.futex_atomic_cmpxchg(uval, uaddr, oldval, newval);
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 549adf6a9b8b..2d9ea11f919a 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -83,8 +83,8 @@ struct uaccess_ops {
 	size_t (*clear_user)(size_t, void __user *);
 	size_t (*strnlen_user)(size_t, const char __user *);
 	size_t (*strncpy_from_user)(size_t, const char __user *, char *);
-	int (*futex_atomic_op)(int op, int __user *, int oparg, int *old);
-	int (*futex_atomic_cmpxchg)(int *, int __user *, int old, int new);
+	int (*futex_atomic_op)(int op, u32 __user *, int oparg, int *old);
+	int (*futex_atomic_cmpxchg)(u32 *, u32 __user *, u32 old, u32 new);
 };
 
 extern struct uaccess_ops uaccess;
diff --git a/arch/s390/lib/uaccess.h b/arch/s390/lib/uaccess.h
index 89a80674e44b..1d2536cb630b 100644
--- a/arch/s390/lib/uaccess.h
+++ b/arch/s390/lib/uaccess.h
@@ -12,12 +12,12 @@ extern size_t copy_from_user_std(size_t, const void __user *, void *);
 extern size_t copy_to_user_std(size_t, void __user *, const void *);
 extern size_t strnlen_user_std(size_t, const char __user *);
 extern size_t strncpy_from_user_std(size_t, const char __user *, char *);
-extern int futex_atomic_cmpxchg_std(int *, int __user *, int, int);
-extern int futex_atomic_op_std(int, int __user *, int, int *);
+extern int futex_atomic_cmpxchg_std(u32 *, u32 __user *, u32, u32);
+extern int futex_atomic_op_std(int, u32 __user *, int, int *);
 
 extern size_t copy_from_user_pt(size_t, const void __user *, void *);
 extern size_t copy_to_user_pt(size_t, void __user *, const void *);
-extern int futex_atomic_op_pt(int, int __user *, int, int *);
-extern int futex_atomic_cmpxchg_pt(int *, int __user *, int, int);
+extern int futex_atomic_op_pt(int, u32 __user *, int, int *);
+extern int futex_atomic_cmpxchg_pt(u32 *, u32 __user *, u32, u32);
 
 #endif /* __ARCH_S390_LIB_UACCESS_H */
diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index b3cebcd52f5c..74833831417f 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -302,7 +302,7 @@ fault:
 		     : "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
 		       "m" (*uaddr) : "cc" );
 
-static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
+static int __futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
 {
 	int oldval = 0, newval, ret;
 
@@ -335,7 +335,7 @@ static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
 	return ret;
 }
 
-int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
+int futex_atomic_op_pt(int op, u32 __user *uaddr, int oparg, int *old)
 {
 	int ret;
 
@@ -354,8 +354,8 @@ int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
 	return ret;
 }
 
-static int __futex_atomic_cmpxchg_pt(int *uval, int __user *uaddr,
-				     int oldval, int newval)
+static int __futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
+				     u32 oldval, u32 newval)
 {
 	int ret;
 
@@ -370,8 +370,8 @@ static int __futex_atomic_cmpxchg_pt(int *uval, int __user *uaddr,
 	return ret;
 }
 
-int futex_atomic_cmpxchg_pt(int *uval, int __user *uaddr,
-			    int oldval, int newval)
+int futex_atomic_cmpxchg_pt(u32 *uval, u32 __user *uaddr,
+			    u32 oldval, u32 newval)
 {
 	int ret;
 
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
index 1d6643c0b95f..bb1a7eed42ce 100644
--- a/arch/s390/lib/uaccess_std.c
+++ b/arch/s390/lib/uaccess_std.c
@@ -255,7 +255,7 @@ size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst)
 		: "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
 		  "m" (*uaddr) : "cc");
 
-int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old)
+int futex_atomic_op_std(int op, u32 __user *uaddr, int oparg, int *old)
 {
 	int oldval = 0, newval, ret;
 
@@ -287,8 +287,8 @@ int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old)
 	return ret;
 }
 
-int futex_atomic_cmpxchg_std(int *uval, int __user *uaddr,
-			     int oldval, int newval)
+int futex_atomic_cmpxchg_std(u32 *uval, u32 __user *uaddr,
+			     u32 oldval, u32 newval)
 {
 	int ret;
 
diff --git a/arch/sh/include/asm/futex-irq.h b/arch/sh/include/asm/futex-irq.h
index 7b701cbd1e84..6cb9f193a95e 100644
--- a/arch/sh/include/asm/futex-irq.h
+++ b/arch/sh/include/asm/futex-irq.h
@@ -3,7 +3,7 @@
 
 #include <asm/system.h>
 
-static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr,
+static inline int atomic_futex_op_xchg_set(int oparg, u32 __user *uaddr,
 					   int *oldval)
 {
 	unsigned long flags;
@@ -20,7 +20,7 @@ static inline int atomic_futex_op_xchg_set(int oparg, int __user *uaddr,
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr,
+static inline int atomic_futex_op_xchg_add(int oparg, u32 __user *uaddr,
 					   int *oldval)
 {
 	unsigned long flags;
@@ -37,7 +37,7 @@ static inline int atomic_futex_op_xchg_add(int oparg, int __user *uaddr,
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr,
+static inline int atomic_futex_op_xchg_or(int oparg, u32 __user *uaddr,
 					  int *oldval)
 {
 	unsigned long flags;
@@ -54,7 +54,7 @@ static inline int atomic_futex_op_xchg_or(int oparg, int __user *uaddr,
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr,
+static inline int atomic_futex_op_xchg_and(int oparg, u32 __user *uaddr,
 					   int *oldval)
 {
 	unsigned long flags;
@@ -71,7 +71,7 @@ static inline int atomic_futex_op_xchg_and(int oparg, int __user *uaddr,
 	return ret;
 }
 
-static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr,
+static inline int atomic_futex_op_xchg_xor(int oparg, u32 __user *uaddr,
 					   int *oldval)
 {
 	unsigned long flags;
@@ -88,12 +88,13 @@ static inline int atomic_futex_op_xchg_xor(int oparg, int __user *uaddr,
 	return ret;
 }
 
-static inline int atomic_futex_op_cmpxchg_inatomic(int *uval,
-						   int __user *uaddr,
-						   int oldval, int newval)
+static inline int atomic_futex_op_cmpxchg_inatomic(u32 *uval,
+						   u32 __user *uaddr,
+						   u32 oldval, u32 newval)
 {
 	unsigned long flags;
-	int ret, prev = 0;
+	int ret;
+	u32 prev = 0;
 
 	local_irq_save(flags);
 
diff --git a/arch/sh/include/asm/futex.h b/arch/sh/include/asm/futex.h
index a8a5125dc9b4..7be39a646fbd 100644
--- a/arch/sh/include/asm/futex.h
+++ b/arch/sh/include/asm/futex.h
@@ -10,7 +10,7 @@
 /* XXX: UP variants, fix for SH-4A and SMP.. */
 #include <asm/futex-irq.h>
 
-static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -21,7 +21,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -65,10 +65,10 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
diff --git a/arch/sparc/include/asm/futex_64.h b/arch/sparc/include/asm/futex_64.h
index e0862200d6a1..444e7bea23bc 100644
--- a/arch/sparc/include/asm/futex_64.h
+++ b/arch/sparc/include/asm/futex_64.h
@@ -30,7 +30,7 @@
 	: "r" (uaddr), "r" (oparg), "i" (-EFAULT)	\
 	: "memory")
 
-static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -38,7 +38,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	int cmparg = (encoded_op << 20) >> 20;
 	int oldval = 0, ret, tem;
 
-	if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(int))))
+	if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
 		return -EFAULT;
 	if (unlikely((((unsigned long) uaddr) & 0x3UL)))
 		return -EINVAL;
@@ -85,8 +85,8 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
 	int ret = 0;
 
diff --git a/arch/tile/include/asm/futex.h b/arch/tile/include/asm/futex.h
index 664b20aa2584..d03ec124a598 100644
--- a/arch/tile/include/asm/futex.h
+++ b/arch/tile/include/asm/futex.h
@@ -29,16 +29,16 @@
 #include <linux/uaccess.h>
 #include <linux/errno.h>
 
-extern struct __get_user futex_set(int __user *v, int i);
-extern struct __get_user futex_add(int __user *v, int n);
-extern struct __get_user futex_or(int __user *v, int n);
-extern struct __get_user futex_andn(int __user *v, int n);
-extern struct __get_user futex_cmpxchg(int __user *v, int o, int n);
+extern struct __get_user futex_set(u32 __user *v, int i);
+extern struct __get_user futex_add(u32 __user *v, int n);
+extern struct __get_user futex_or(u32 __user *v, int n);
+extern struct __get_user futex_andn(u32 __user *v, int n);
+extern struct __get_user futex_cmpxchg(u32 __user *v, int o, int n);
 
 #ifndef __tilegx__
-extern struct __get_user futex_xor(int __user *v, int n);
+extern struct __get_user futex_xor(u32 __user *v, int n);
 #else
-static inline struct __get_user futex_xor(int __user *uaddr, int n)
+static inline struct __get_user futex_xor(u32 __user *uaddr, int n)
 {
 	struct __get_user asm_ret = __get_user_4(uaddr);
 	if (!asm_ret.err) {
@@ -53,7 +53,7 @@ static inline struct __get_user futex_xor(int __user *uaddr, int n)
 }
 #endif
 
-static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -65,7 +65,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -119,12 +119,12 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	return ret;
 }
 
-static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-						int oldval, int newval)
+static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+						u32 oldval, u32 newval)
 {
 	struct __get_user asm_ret;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	asm_ret = futex_cmpxchg(uaddr, oldval, newval);
diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index 884c0b5676f4..d09bb03653f0 100644
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -37,7 +37,7 @@
 		       "+m" (*uaddr), "=&r" (tem)		\
 		     : "r" (oparg), "i" (-EFAULT), "1" (0))
 
-static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -48,7 +48,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
@@ -109,8 +109,8 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
 	return ret;
 }
 
-static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-						int oldval, int newval)
+static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+						u32 oldval, u32 newval)
 {
 	int ret = 0;
 
@@ -120,7 +120,7 @@ static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
 		return -ENOSYS;
 #endif
 
-	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
index 132bf5227b44..01f227e14254 100644
--- a/include/asm-generic/futex.h
+++ b/include/asm-generic/futex.h
@@ -6,7 +6,7 @@
 #include <asm/errno.h>
 
 static inline int
-futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
 {
 	int op = (encoded_op >> 28) & 7;
 	int cmp = (encoded_op >> 24) & 15;
@@ -16,7 +16,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
 		oparg = 1 << oparg;
 
-	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
 	pagefault_disable();
@@ -48,8 +48,8 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
 }
 
 static inline int
-futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
-			      int oldval, int newval)
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
 {
 	return -ENOSYS;
 }

From 2e12978a9f7a7abd54e8eb9ce70a7718767b8b2c Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Wed, 22 Dec 2010 14:18:50 +0800
Subject: [PATCH 06/11] futex,plist: Pass the real head of the priority list to
 plist_del()

Some plist_del()s in kernel/futex.c are passed a faked head of the
priority list.

It does not fail because the current code does not require the real head
in plist_del(). The current code of plist_del() just uses the head for checking,
so it will not cause a bad result even when we use a faked head.

But it is undocumented usage:

/**
 * plist_del - Remove a @node from plist.
 *
 * @node:	&struct plist_node pointer - entry to be removed
 * @head:	&struct plist_head pointer - list head
 */

The document says that the @head is the "list head" head of the priority list.

In futex code, several places use "plist_del(&q->list, &q->list.plist);",
they pass a fake head. We need to fix them all.

Thanks to Darren Hart for many suggestions.

Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by:  Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D11984A.5030203@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/futex.c | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index b766d28accd6..6feeea4f8f15 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -775,6 +775,24 @@ retry:
 	return ret;
 }
 
+/**
+ * __unqueue_futex() - Remove the futex_q from its futex_hash_bucket
+ * @q:	The futex_q to unqueue
+ *
+ * The q->lock_ptr must not be NULL and must be held by the caller.
+ */
+static void __unqueue_futex(struct futex_q *q)
+{
+	struct futex_hash_bucket *hb;
+
+	if (WARN_ON(!q->lock_ptr || !spin_is_locked(q->lock_ptr)
+			|| plist_node_empty(&q->list)))
+		return;
+
+	hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock);
+	plist_del(&q->list, &hb->chain);
+}
+
 /*
  * The hash bucket lock must be held when this is called.
  * Afterwards, the futex_q must not be accessed.
@@ -792,7 +810,7 @@ static void wake_futex(struct futex_q *q)
 	 */
 	get_task_struct(p);
 
-	plist_del(&q->list, &q->list.plist);
+	__unqueue_futex(q);
 	/*
 	 * The waiting task can free the futex_q as soon as
 	 * q->lock_ptr = NULL is written, without taking any locks. A
@@ -1100,8 +1118,7 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
 	get_futex_key_refs(key);
 	q->key = *key;
 
-	WARN_ON(plist_node_empty(&q->list));
-	plist_del(&q->list, &q->list.plist);
+	__unqueue_futex(q);
 
 	WARN_ON(!q->rt_waiter);
 	q->rt_waiter = NULL;
@@ -1504,8 +1521,7 @@ retry:
 			spin_unlock(lock_ptr);
 			goto retry;
 		}
-		WARN_ON(plist_node_empty(&q->list));
-		plist_del(&q->list, &q->list.plist);
+		__unqueue_futex(q);
 
 		BUG_ON(q->pi_state);
 
@@ -1525,8 +1541,7 @@ retry:
 static void unqueue_me_pi(struct futex_q *q)
 	__releases(q->lock_ptr)
 {
-	WARN_ON(plist_node_empty(&q->list));
-	plist_del(&q->list, &q->list.plist);
+	__unqueue_futex(q);
 
 	BUG_ON(!q->pi_state);
 	free_pi_state(q->pi_state);
@@ -2167,7 +2182,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
 		 * We were woken prior to requeue by a timeout or a signal.
 		 * Unqueue the futex_q and determine which it was.
 		 */
-		plist_del(&q->list, &q->list.plist);
+		plist_del(&q->list, &hb->chain);
 
 		/* Handle spurious wakeups gracefully */
 		ret = -EWOULDBLOCK;

From 017f2b239dabb2740b91df162e004371b861f371 Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Tue, 21 Dec 2010 17:55:10 +0800
Subject: [PATCH 07/11] futex,plist: Remove debug lock assignment from
 plist_node

The original code uses &plist_node->plist as the fake head of
the priority list for plist_del(), these debug locks in
the fake head are needed for CONFIG_DEBUG_PI_LIST.

But now we always pass the real head to plist_del(), the debug locks
in plist_node will not be used, so we remove these assignments.

Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by:  Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D10797E.7040803@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/futex.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 6feeea4f8f15..9fe913141ec9 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1089,9 +1089,6 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
 		plist_del(&q->list, &hb1->chain);
 		plist_add(&q->list, &hb2->chain);
 		q->lock_ptr = &hb2->lock;
-#ifdef CONFIG_DEBUG_PI_LIST
-		q->list.plist.spinlock = &hb2->lock;
-#endif
 	}
 	get_futex_key_refs(key2);
 	q->key = *key2;
@@ -1124,9 +1121,6 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
 	q->rt_waiter = NULL;
 
 	q->lock_ptr = &hb->lock;
-#ifdef CONFIG_DEBUG_PI_LIST
-	q->list.plist.spinlock = &hb->lock;
-#endif
 
 	wake_up_state(q->task, TASK_NORMAL);
 }
@@ -1474,9 +1468,6 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
 	prio = min(current->normal_prio, MAX_RT_PRIO);
 
 	plist_node_init(&q->list, prio);
-#ifdef CONFIG_DEBUG_PI_LIST
-	q->list.plist.spinlock = &hb->lock;
-#endif
 	plist_add(&q->list, &hb->chain);
 	q->task = current;
 	spin_unlock(&hb->lock);

From bf6a9b8336ba12672755c2ae898b0abe42c7a5ac Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Tue, 21 Dec 2010 17:55:14 +0800
Subject: [PATCH 08/11] plist: Shrink struct plist_head

struct plist_head is used in struct task_struct as well as struct
rtmutex. If we can make it smaller, it will also make these structures
smaller as well.

The field prio_list in struct plist_head is seldom used and we can get
its information from the plist_nodes. Removing this field will decrease
the size of plist_head by half.

Signed-off-by:  Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D107982.9090700@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/plist.h | 47 +++++++++++++++++++------------------
 lib/plist.c           | 54 ++++++++++++++++++++++++++++---------------
 2 files changed, 59 insertions(+), 42 deletions(-)

diff --git a/include/linux/plist.h b/include/linux/plist.h
index 7254eda078e5..c9b9f322c8d8 100644
--- a/include/linux/plist.h
+++ b/include/linux/plist.h
@@ -31,15 +31,17 @@
  *
  * Simple ASCII art explanation:
  *
- * |HEAD          |
- * |              |
- * |prio_list.prev|<------------------------------------|
- * |prio_list.next|<->|pl|<->|pl|<--------------->|pl|<-|
- * |10            |   |10|   |21|   |21|   |21|   |40|   (prio)
- * |              |   |  |   |  |   |  |   |  |   |  |
- * |              |   |  |   |  |   |  |   |  |   |  |
- * |node_list.next|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-|
- * |node_list.prev|<------------------------------------|
+ * pl:prio_list (only for plist_node)
+ * nl:node_list
+ *   HEAD|             NODE(S)
+ *       |
+ *       ||------------------------------------|
+ *       ||->|pl|<->|pl|<--------------->|pl|<-|
+ *       |   |10|   |21|   |21|   |21|   |40|   (prio)
+ *       |   |  |   |  |   |  |   |  |   |  |
+ *       |   |  |   |  |   |  |   |  |   |  |
+ * |->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<->|nl|<-|
+ * |-------------------------------------------|
  *
  * The nodes on the prio_list list are sorted by priority to simplify
  * the insertion of new nodes. There are no nodes with duplicate
@@ -78,7 +80,6 @@
 #include <linux/spinlock_types.h>
 
 struct plist_head {
-	struct list_head prio_list;
 	struct list_head node_list;
 #ifdef CONFIG_DEBUG_PI_LIST
 	raw_spinlock_t *rawlock;
@@ -88,7 +89,8 @@ struct plist_head {
 
 struct plist_node {
 	int			prio;
-	struct plist_head	plist;
+	struct list_head	prio_list;
+	struct list_head	node_list;
 };
 
 #ifdef CONFIG_DEBUG_PI_LIST
@@ -100,7 +102,6 @@ struct plist_node {
 #endif
 
 #define _PLIST_HEAD_INIT(head)				\
-	.prio_list = LIST_HEAD_INIT((head).prio_list),	\
 	.node_list = LIST_HEAD_INIT((head).node_list)
 
 /**
@@ -133,7 +134,8 @@ struct plist_node {
 #define PLIST_NODE_INIT(node, __prio)			\
 {							\
 	.prio  = (__prio),				\
-	.plist = { _PLIST_HEAD_INIT((node).plist) },	\
+	.prio_list = LIST_HEAD_INIT((node).prio_list),	\
+	.node_list = LIST_HEAD_INIT((node).node_list),	\
 }
 
 /**
@@ -144,7 +146,6 @@ struct plist_node {
 static inline void
 plist_head_init(struct plist_head *head, spinlock_t *lock)
 {
-	INIT_LIST_HEAD(&head->prio_list);
 	INIT_LIST_HEAD(&head->node_list);
 #ifdef CONFIG_DEBUG_PI_LIST
 	head->spinlock = lock;
@@ -160,7 +161,6 @@ plist_head_init(struct plist_head *head, spinlock_t *lock)
 static inline void
 plist_head_init_raw(struct plist_head *head, raw_spinlock_t *lock)
 {
-	INIT_LIST_HEAD(&head->prio_list);
 	INIT_LIST_HEAD(&head->node_list);
 #ifdef CONFIG_DEBUG_PI_LIST
 	head->rawlock = lock;
@@ -176,7 +176,8 @@ plist_head_init_raw(struct plist_head *head, raw_spinlock_t *lock)
 static inline void plist_node_init(struct plist_node *node, int prio)
 {
 	node->prio = prio;
-	plist_head_init(&node->plist, NULL);
+	INIT_LIST_HEAD(&node->prio_list);
+	INIT_LIST_HEAD(&node->node_list);
 }
 
 extern void plist_add(struct plist_node *node, struct plist_head *head);
@@ -188,7 +189,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
  * @head:	the head for your list
  */
 #define plist_for_each(pos, head)	\
-	 list_for_each_entry(pos, &(head)->node_list, plist.node_list)
+	 list_for_each_entry(pos, &(head)->node_list, node_list)
 
 /**
  * plist_for_each_safe - iterate safely over a plist of given type
@@ -199,7 +200,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
  * Iterate over a plist of given type, safe against removal of list entry.
  */
 #define plist_for_each_safe(pos, n, head)	\
-	 list_for_each_entry_safe(pos, n, &(head)->node_list, plist.node_list)
+	 list_for_each_entry_safe(pos, n, &(head)->node_list, node_list)
 
 /**
  * plist_for_each_entry	- iterate over list of given type
@@ -208,7 +209,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
  * @mem:	the name of the list_struct within the struct
  */
 #define plist_for_each_entry(pos, head, mem)	\
-	 list_for_each_entry(pos, &(head)->node_list, mem.plist.node_list)
+	 list_for_each_entry(pos, &(head)->node_list, mem.node_list)
 
 /**
  * plist_for_each_entry_safe - iterate safely over list of given type
@@ -220,7 +221,7 @@ extern void plist_del(struct plist_node *node, struct plist_head *head);
  * Iterate over list of given type, safe against removal of list entry.
  */
 #define plist_for_each_entry_safe(pos, n, head, m)	\
-	list_for_each_entry_safe(pos, n, &(head)->node_list, m.plist.node_list)
+	list_for_each_entry_safe(pos, n, &(head)->node_list, m.node_list)
 
 /**
  * plist_head_empty - return !0 if a plist_head is empty
@@ -237,7 +238,7 @@ static inline int plist_head_empty(const struct plist_head *head)
  */
 static inline int plist_node_empty(const struct plist_node *node)
 {
-	return plist_head_empty(&node->plist);
+	return list_empty(&node->node_list);
 }
 
 /* All functions below assume the plist_head is not empty. */
@@ -285,7 +286,7 @@ static inline int plist_node_empty(const struct plist_node *node)
 static inline struct plist_node *plist_first(const struct plist_head *head)
 {
 	return list_entry(head->node_list.next,
-			  struct plist_node, plist.node_list);
+			  struct plist_node, node_list);
 }
 
 /**
@@ -297,7 +298,7 @@ static inline struct plist_node *plist_first(const struct plist_head *head)
 static inline struct plist_node *plist_last(const struct plist_head *head)
 {
 	return list_entry(head->node_list.prev,
-			  struct plist_node, plist.node_list);
+			  struct plist_node, node_list);
 }
 
 #endif
diff --git a/lib/plist.c b/lib/plist.c
index 1471988d9190..8c614d0e6c35 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -59,7 +59,8 @@ static void plist_check_head(struct plist_head *head)
 		WARN_ON_SMP(!raw_spin_is_locked(head->rawlock));
 	if (head->spinlock)
 		WARN_ON_SMP(!spin_is_locked(head->spinlock));
-	plist_check_list(&head->prio_list);
+	if (!plist_head_empty(head))
+		plist_check_list(&plist_first(head)->prio_list);
 	plist_check_list(&head->node_list);
 }
 
@@ -75,25 +76,33 @@ static void plist_check_head(struct plist_head *head)
  */
 void plist_add(struct plist_node *node, struct plist_head *head)
 {
-	struct plist_node *iter;
+	struct plist_node *first, *iter, *prev = NULL;
+	struct list_head *node_next = &head->node_list;
 
 	plist_check_head(head);
 	WARN_ON(!plist_node_empty(node));
+	WARN_ON(!list_empty(&node->prio_list));
 
-	list_for_each_entry(iter, &head->prio_list, plist.prio_list) {
-		if (node->prio < iter->prio)
-			goto lt_prio;
-		else if (node->prio == iter->prio) {
-			iter = list_entry(iter->plist.prio_list.next,
-					struct plist_node, plist.prio_list);
-			goto eq_prio;
+	if (plist_head_empty(head))
+		goto ins_node;
+
+	first = iter = plist_first(head);
+
+	do {
+		if (node->prio < iter->prio) {
+			node_next = &iter->node_list;
+			break;
 		}
-	}
 
-lt_prio:
-	list_add_tail(&node->plist.prio_list, &iter->plist.prio_list);
-eq_prio:
-	list_add_tail(&node->plist.node_list, &iter->plist.node_list);
+		prev = iter;
+		iter = list_entry(iter->prio_list.next,
+				struct plist_node, prio_list);
+	} while (iter != first);
+
+	if (!prev || prev->prio != node->prio)
+		list_add_tail(&node->prio_list, &iter->prio_list);
+ins_node:
+	list_add_tail(&node->node_list, node_next);
 
 	plist_check_head(head);
 }
@@ -108,14 +117,21 @@ void plist_del(struct plist_node *node, struct plist_head *head)
 {
 	plist_check_head(head);
 
-	if (!list_empty(&node->plist.prio_list)) {
-		struct plist_node *next = plist_first(&node->plist);
+	if (!list_empty(&node->prio_list)) {
+		if (node->node_list.next != &head->node_list) {
+			struct plist_node *next;
 
-		list_move_tail(&next->plist.prio_list, &node->plist.prio_list);
-		list_del_init(&node->plist.prio_list);
+			next = list_entry(node->node_list.next,
+					struct plist_node, node_list);
+
+			/* add the next plist_node into prio_list */
+			if (list_empty(&next->prio_list))
+				list_add(&next->prio_list, &node->prio_list);
+		}
+		list_del_init(&node->prio_list);
 	}
 
-	list_del_init(&node->plist.node_list);
+	list_del_init(&node->node_list);
 
 	plist_check_head(head);
 }

From 6d55da53db3d9b911f69f2ce1e5fb8943eafe057 Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Tue, 21 Dec 2010 17:55:18 +0800
Subject: [PATCH 09/11] plist: Add priority list test

Add test code for checking plist when the kernel is booting.

Signed-off-by:  Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D107986.1010302@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 lib/plist.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 1 deletion(-)

diff --git a/lib/plist.c b/lib/plist.c
index 8c614d0e6c35..0ae7e6431726 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -28,6 +28,8 @@
 
 #ifdef CONFIG_DEBUG_PI_LIST
 
+static struct plist_head test_head;
+
 static void plist_check_prev_next(struct list_head *t, struct list_head *p,
 				  struct list_head *n)
 {
@@ -54,7 +56,7 @@ static void plist_check_list(struct list_head *top)
 
 static void plist_check_head(struct plist_head *head)
 {
-	WARN_ON(!head->rawlock && !head->spinlock);
+	WARN_ON(head != &test_head && !head->rawlock && !head->spinlock);
 	if (head->rawlock)
 		WARN_ON_SMP(!raw_spin_is_locked(head->rawlock));
 	if (head->spinlock)
@@ -135,3 +137,80 @@ void plist_del(struct plist_node *node, struct plist_head *head)
 
 	plist_check_head(head);
 }
+
+#ifdef CONFIG_DEBUG_PI_LIST
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+static struct plist_node __initdata test_node[241];
+
+static void __init plist_test_check(int nr_expect)
+{
+	struct plist_node *first, *prio_pos, *node_pos;
+
+	if (plist_head_empty(&test_head)) {
+		BUG_ON(nr_expect != 0);
+		return;
+	}
+
+	prio_pos = first = plist_first(&test_head);
+	plist_for_each(node_pos, &test_head) {
+		if (nr_expect-- < 0)
+			break;
+		if (node_pos == first)
+			continue;
+		if (node_pos->prio == prio_pos->prio) {
+			BUG_ON(!list_empty(&node_pos->prio_list));
+			continue;
+		}
+
+		BUG_ON(prio_pos->prio > node_pos->prio);
+		BUG_ON(prio_pos->prio_list.next != &node_pos->prio_list);
+		prio_pos = node_pos;
+	}
+
+	BUG_ON(nr_expect != 0);
+	BUG_ON(prio_pos->prio_list.next != &first->prio_list);
+}
+
+static int  __init plist_test(void)
+{
+	int nr_expect = 0, i, loop;
+	unsigned int r = local_clock();
+
+	printk(KERN_INFO "start plist test\n");
+	plist_head_init(&test_head, NULL);
+	for (i = 0; i < ARRAY_SIZE(test_node); i++)
+		plist_node_init(test_node + i, 0);
+
+	for (loop = 0; loop < 1000; loop++) {
+		r = r * 193939 % 47629;
+		i = r % ARRAY_SIZE(test_node);
+		if (plist_node_empty(test_node + i)) {
+			r = r * 193939 % 47629;
+			test_node[i].prio = r % 99;
+			plist_add(test_node + i, &test_head);
+			nr_expect++;
+		} else {
+			plist_del(test_node + i, &test_head);
+			nr_expect--;
+		}
+		plist_test_check(nr_expect);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(test_node); i++) {
+		if (plist_node_empty(test_node + i))
+			continue;
+		plist_del(test_node + i, &test_head);
+		nr_expect--;
+		plist_test_check(nr_expect);
+	}
+
+	printk(KERN_INFO "end plist test\n");
+	return 0;
+}
+
+module_init(plist_test);
+
+#endif

From 6e0aa9f8a8190e0879a29bd67aa606b51734a122 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 14 Mar 2011 10:34:35 +0100
Subject: [PATCH 10/11] futex: Deobfuscate handle_futex_death()

handle_futex_death() uses futex_atomic_cmpxchg_inatomic() without
disabling page faults. That's ok, but totally non obvious.

We don't hold locks so we actually can and want to fault here, because
the get_user() before futex_atomic_cmpxchg_inatomic() does not
guarantee a R/W mapping.

We could just add a big fat comment to explain this, but actually
changing the code so that the functionality is entirely clear is
better.

Use the helper function which disables page faults around the
futex_atomic_cmpxchg_inatomic() and handle a fault with a call to
fault_in_user_writeable() as all other places in the futex code do as
well.

Pointed-out-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Darren Hart <darren@dvhart.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
LKML-Reference: <alpine.LFD.2.00.1103141126590.2787@localhost6.localdomain6>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/futex.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index c6bef6e404fe..e9251d934f7d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2458,9 +2458,20 @@ retry:
 		 * userspace.
 		 */
 		mval = (uval & FUTEX_WAITERS) | FUTEX_OWNER_DIED;
-		if (futex_atomic_cmpxchg_inatomic(&nval, uaddr, uval, mval))
-			return -1;
-
+		/*
+		 * We are not holding a lock here, but we want to have
+		 * the pagefault_disable/enable() protection because
+		 * we want to handle the fault gracefully. If the
+		 * access fails we try to fault in the futex with R/W
+		 * verification via get_user_pages. get_user() above
+		 * does not guarantee R/W access. If that fails we
+		 * give up and leave the futex locked.
+		 */
+		if (cmpxchg_futex_value_locked(&nval, uaddr, uval, mval)) {
+			if (fault_in_user_writeable(uaddr))
+				return -1;
+			goto retry;
+		}
 		if (nval != uval)
 			goto retry;
 

From 07d5ecae2940ddd77746e2fb597dcf57d3c2e277 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 14 Mar 2011 20:00:30 +0100
Subject: [PATCH 11/11] arm: Remove bogus comment in
 futex_atomic_cmpxchg_inatomic()

commit 522d7dec(futex: Remove redundant pagefault_disable in
futex_atomic_cmpxchg_inatomic()) added a bogus comment.

/* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic
 * call sites. */

Bogus in two aspects:

1) pagefault_disable != preempt_disable even if the mechanism we use
   is the same

2) we have a call site which deliberately does not disable pagefaults
   as it wants the possible fault to be handled - though that has been
   changed for consistency reasons now.

Sigh. I really should have seen that when committing the above. :(

Catched-by-and-rightfully-ranted-at-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <alpine.LFD.2.00.1103141126590.2787@localhost6.localdomain6>
Cc: Michel Lespinasse <walken@google.com>
Cc: Darren Hart <darren@dvhart.com>
---
 arch/arm/include/asm/futex.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 0e29d8e6a5c2..199a6b6de7f4 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -97,9 +97,6 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 		return -EFAULT;
 
-	/* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic
-	 * call sites. */
-
 	__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
 	"1:	" T(ldr) "	%1, [%4]\n"
 	"	teq	%1, %2\n"